They may be useful in areas like parking lots where its just a flat surface and nothing holding the leaves in place. I think using backpack blower or using a mower to mulch/bag leaves is faster and more thorough for lawn and resi work.

I have one just like that, except mine has a briggs. I paid $150.00 and bought a hose kit for it. I does OK picking up leaves but to tell you the truth I would never use the BillyGoat for leaves or power raking, just to messy and a pain to empty that many times. I would rather blow or rake leave or grass onto a tarp and load them, than use the BillyGoat. But like the previous poster said it does wonders on hard surface's and the hose reaches into places that you can't get to with the blower or rakes. I find my BillyGoat is worth it for those reasons alone. When I rake grass or blow leaves I don't worry about getting every little bit. I get the rest with my mowers. Then clean all hard surface's with the BillyGoat. The properties end up looking great.
Hope this helps.